Railway signaling system.



H. A. WAGNER.

RAILWAY SIGNALING SYSTEM.

APPLICATION FILED SEPT. 14. 1907.

Patented Apr. 30, 1918.

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H. A. WAGNER. RAILWAY SIGNALING SYSTEM. APPLICATION man SEPT- 14, I907.

Patented Apr. 30, 1918.

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HERBERT A. WAGNER, OF N EW YORK, 15]. Y.

RAILWAY SIGNALING SYSTEM.

Application filed September 14, 1967.

To all whom it may concern:

Be it known that I, HERBERT A. WAGNER, a citizen of the United States, residing in the city of New York, in the county and State of New York, have invented certain new and useful Improvements in Railway Signaling Systems, of which the following is a specification.

My invention relates to an electric signaling system for railroads and is especially applicable to railroads operated by electric traction.

My invention is applicable and is especially designed for use in connection with what is known as the block system of railway signaling in which the track is divided into blocks and a semaphore or movable arm or other form of signal at the entrance of each block is automatically operated by the movement of the train past the signal into the block controlled by the signal, the wheels and axles of the train shunting a signal-controlling current in the rails and thereby causing the operation of the signal. My invention is not, however, limited to this specific character of system and in using the term signaling system I desire it to be understood that I intend to include not only a system in which visible signals are operated, but also a system in which any kind of signal or safety device or means for controlling movement of trains is to be auto matically operated by the passage of a train along the track.

Various features of my invention relate particularly to that general form of railway signaling system which is d sclosed and broadly claimed in an applicatlon for Letters Patent of the United States filed by one Clyde J. Coleman on July 12, 1907, Serial No. 883,366. r

In that form of signaling system the rails of the track are made electrically or conductively continuous and are supplied at intervals with signal-controlling current from suitable sources giving a diflerence of potential to the rails. The current supplied by each source to the rails is confined to a distinct portion of the track by means of conducting bonds connecting the two rails of the track on either side of the source and forming points of substantially zero difi'erence of potential between the rails. To ef-' fect this result the bonds are of negligible impedance, by which I mean that they afford so little obstruction to the passage of Specification of Letters latent.

Patented Apr. 3% JWIfi. Serial No. 392,836.

the signal-controlling current that no more than a negligible current could pass from one source of signal-controlling current to the rails beyond the conducting bond on either side of the source.

My invention involves the operation of the signals or safety devices by electro-responsive devices, such as relays for example, each of which receives a current normally determined by some definite proportion of the drop of potential between a source of supply and a conducting bond. The electroresponsive devices are connected to the track in such a way that the difl'erence of potential applied to them when the track is clear will energize them for one operating position, whereas when the track is not clear and the diii'erence of potential between the rails is reduced by reason of the low resistance connection established between them by car wheels and axles, the electro-responsive devices will become sufliciently de'e'nergized to take another position which will cause the signal to assume the danger position. In

order to obtain a sharp line of demarcation.

between blocks so that there will be no undesirable overlap which might cause a signal to go to danger too early or too late, I provide that the normal difierence of potential acting upon the electro-responsive devices shall be that which exists between the rails at points in the track a relatively short distance from the nearby conducting bonds, and I prefer to obtain this normal difference of potential by connecting the coil of the electro-responsive device across the track so as to obtain in shunt with the coil the resistance or impedance of both rails from their points of connection with the coil to their points of connection with the conducting bond.

The invention is equally applicable to what is known as the normal danger sys-- tem, or to a normal clear system. It enables me to dispense with the disadvantages resulting from any attempt to divide the track into insulated sections while using the track for carrying the traction current, and also to avoid any disadvantages due to undesirable overlapping because I provide a sharp line of demarcation between the blocks. These results I attain by an extremely simple system employing only well known and simple forms of apparatus, and without requiring that reliance to be placed upon the use of a number of different phases or a number of different frequencies of alternating current, or any complexities of this character. Moreover, I am enabled to avoid the use of any inductive bonds, or any use of special kinds of transforming apparatus.

My invention is applicable whether the signal-controlling current be a unidirectional constant current, or an intermittent or alternating current; and my invention is applicable whatever may be the character of current employed for traction purposes.

I will now describe the constructions shown embodying my invention and will thereafter point out my invention in claims.

In the drawings accompanying this specification,

Figure 1 illustrates a system embodying my broad invention in a simple form, the system being shown as a normal clear block system operating home signals only.

Fig. 2 is a diagram illustrating the application of my invention to a normal danger system and showing the operation of both home and distant signals.

Referring first to Fig. 1, A, A represent the two electrically or conductively continuous rails of a track. The operation of cars on this track is to be under the control of the signaling arms B, B, B placed at the entrance of the blocks 2, 3 and 4:. G, C and O are the bonds of negligible impedance which, in the present instance, are placed at the termini of the blocks. By negligible impedance I mean that these bonds should be of such a character as to offer substantially no obstruction to the flow of the signal-controlling current from one rail to the other, thereby establishing a substantially zero difference of potential between the two rails at the points where they are connected to these bonds. If the signal- ,controlling current be an alternating or other inductive current, the bonds should have a negligible ohmic resistance and also a negligible inductance, while only the former characteristic is essential if the signal-controlling current be a unidirectional or non-inductive current.

Between each pair of bonds the rails are supplied from a source of signal-controlling current. In the present instanceIhave shown an alternating current generator D which supplies the primaries E, E of transformers, the secondaries F, F of which are connected across the rails and preferably about midway in the block or midway between two conducting bonds. When any block is entirely clear of trains a certain definite difference of potential between the rails of the track is established at the center of the block, whereas at each end of the block, because of the conducting bonds, the difference of potential is zero, the current from each transformer F, F dividing between two circuits, one through the rails and a conducting bond on one side of the secondary of the transformer, and the other through the rails and the conducting bond at the other side of the secondary.

At any given point between the point of connection of a track-supplying current source or transformer secondary and a bond the difference of potential between the rails will bear a certain value intermediate between zero and the maximum difference of potential given by the source or transformer secondary, but if a car is close enough to the point of connection of a track-supplying source or is between such point of connection and the given point or is beyond the given point but near enough to substantially vary the point of zero difference of potential between the rails of the track, there will be no substantial difference of potential at such given point. Relying upon this principle I supply electro-responsive devices comprising relays governed by coils H to H which are connected across the rails in order that a definite diiference of potential may be applied to them when the track is clear. These coils each operate arms IL in opposition to a tension device such as the weight it, the relay being so designed that when the normal difference of potential is across the coil the power of the latter overcomes the opposing tension device and closes a local circuit designed to operate the signal and hold it in a clear position as hereinafter described. As indicated, each relay is connected to the rails at a point in the track sufficiently close to a conducting bond so that there will be a sharp line of demarcation between blocks, and yet is sufficiently far from the bond so that there will be a substantial normal difference of potential acting uponthe relay.

In the present instance I have shown the signal arms B, B, B directly controlled by solenoids J, J, J in local circuits supplied by batteries K, K, K WVhen any local circuit is closed the signal is held to clear by its solenoid, but the circuit of such solenoid includes in series two of the switches controlled by the coils H to H". The two switches in each local circuit are the switches governed by those coils which are connected to the rails in a block on each side of the point where the signal controlling current is supplied to the rails of that block. Thus the arm B controls block 2. The circuit of the solenoid J for the arm B includes the relays governed by the coils H H which are connected respectively at points adjacent to opposite ends of the block 2. In Fig. l the block 2 is shown as being free of any car and therefore both relays H and H are energized to maintain the integrity of the circuit of the solenoid J, whereby solenoid J receives current from the battery 6 traction current.

meagre K and holds the arm B atsafety. Tn block 3, however, I have indicated at L two axles and pairs of wheels of a car or train. These are located between the transformer secondary F and the points of connection of the coil H so that there is substantially zero difference of potential across the termin'als of the coihH causing this coil to be come deenergized, and so opening the circuit between the battery K and the solenoid J" and setting the arm B to danger. As the train L moves to the right it will next so nearly short circuit the secondary F as to cause the coil H to become deenergized and the circuit to the solenoid J will therefore be open at two oints. A further movement of the train to t e right and beyond the secondary F will finally cause the difierence of potential across H3 to rise to a point that will energize that coil and close the local circuit at thispoint, but owing to the shunting action of the train the local circuit will still be open atthe relay governed by coil H and will remain open at this point maintaining the arm B at danger until the rear endof the train reaches a point so close to the bond C as to cause nearly the normal difference of potential to be felt by the coil H By this time the train will be practically out of the block 3, and the greater part of the train will have passed the bond C so as to operate the arm 13 by the deenergizing of the coil H The system therefore meets the usualrequirements of a block system, that a signal must always be at danger when there is a train in any part of the block protected by thatsignal, and in this system the line of demarcation between. adjacent blocks is a sharp one inasmuch as the various coils H to H may be placed near enough tothe bonds 0 to C to cause no appreciable overlapping.

The system also fulfils the requirement that the signalshould go to danger if there is a broken rail, because any break in the rails of the track A, A between any source and the points of relay connection will cause a cessation of the signal-controlling currentand cause the relay in series with the broken rail to become deenergized. Should the rail break between the points of relay connection and the adjacent bond the result would be that the corresponding relay, H or H, etc., would receive a current of much higher potential, substantially the full potential of the source, and I therefore provide fuses s or other overload circuit breakers, in the circuits of such relays, which would break such circuits in the event of a broken rail between the point of relay connection and a connecting bond.

If electric traction is to be used for train propulsion, the rails of the track would naturally be used as return conductors for the The rails being electrically continuous, would form the best possible electric conductor for tractlon current, and the heavy cross-bonds of low resistance would facilitate the equalization of this cure normal danger system. So far as applicable the same letters of reference are applied in this figure as in Fig. 1. In Fig. 2 the home and distant signals 18 and M are both shown at danger, and a train L is shown in the block 2. The home and distant signals B and M are both shown as cleared by the approaching train L in block 2, there being no train in block 3 or block f to maintain either of these signals at danger. A

In Fig. 2 the coils H H H" and H govern movable contact fingers and correspond to the coils Hto H of Fig. 1, while the coils H, H H and similar movable contact fingers which, however, have back contacts is. included in the local signal circuit of the block ahead so that the local signal. circuit of the block ahead cannot be closed to set its signals at clear except by a train approaching the block while maintaining the signal behind the train at danger. Tn Fig. 2 the local cir cuits are shown as supplied by transformers Nto N In series with each of the coils J to J controlling the home signals are coils U to controlling movable contact fingers each i in series with the corresponding coil, P to F controlling a distant signal. Whenever, therefore, a home signal is at danger because of the deenergizing of its coil J or J, eta,

the circuit of the corresponding coil P or P, etc, is open, and therefore the distant signal, M or M, etc, must also be at danger.

The home and distant signals B, M, are both atdanger, and cannot be cleared because the train L in block 2 is at such a position as to deenergize the coil H and thereby open the circuit from the secondary of transformer N to the coils J and O. This same circuit to the coils J and 0 is also H of Fig. 2 govern opened at the back contacts K because it is assumed that there is no train in the block 1.

The signals B and M are both cleared because the train L in block 2 has deenergized the coil H closing at the back contacts k the circuit of the solenoid J and coil 0. circuit from the transformer N is completed through the front contacts of the relay H As there is no train in block 3 the and H of block 3, and thence through the back contacts 70 of the relay H The cur- 1 I rent which clears the home signal B closes the switch controlled by the coil 0 and the distant signal M is put to clear because the circuit of its actuating coil 1? is completed. by the front contacts of the relays of the next block ahead, block 4. The actuating coil J of the home signalB is therefore in the local circuit of the transformer l while the actuating coil P of the distant signal M is in the local circuit of the transformer N If there were a train in block 4 one of the relays of that block would open its front contacts, wherefore the distant signal M would be held at danger despite the clear- 7 ing action of the train L in block 2.

There being no train in block 3, both signals B and M are at danger because the circuit of the actuating coil J 2 is open at the back contacts of the relay H Inasmuch as there is no train in the block 4, the circuit of the coil J 2 is-otherwise complete, and if a train should enter block 3 the home signal B would be cleared. The distant signalM would not be cleared, however, because there trolling signals B and. M.

In Fig. 2 I have indicated that step'up transformers Q might be used between the coils H to H and the track connections. This may be desirable in order to increase the'potential acrossthe coils and permit the use of smaller wires to and in the coil.

It is obvious that various modifications may be made in the constructions and. arrangements of circuits shown and above particularly described, all coming, however, within the principle and scope of my invention.

Having thus described my invention, what I claim asnew and desire to secure by Letters Patent is:

1. In a railway signaling system, electrically continuous track rails, a conducting bond connecting the opposite rails of the track, a source of electric current arranged to create a difierence of electric potential between the rails of the track at a point distant from said bond, and an electro-responsive signal controlling device operatively related to the track rails to receive a substantial-working current determined by the drop of the potential in a definite portion of the track between said bond and said source.

2. In a railway signaling system, electrically continuous track rails, a conducting bond connecting the opposite rails of the track, a source of electric current arranged to create a difference of potential between the rails of the track at a point distant from said bond, and an electro-responsive signal controlling device connected with the track rails at a point intermediate the source and bond so as to receive a substantial working current determined by the drop of potential in a definite portion of the track between said bond and said source.

3. In a railway signaling system, electrically continuous track rails, a bond of negligible impedance connecting the opposite rails of the track, a source of electric current arranged to create a difference of potential between the rails of the track at a point distant from said bond and an electroresponsive signal controlling device operatively related to the track rails to receive a substantial working current determined by the drop of potential in a definite portion of the track between said bond and said source.

l. In a railway signaling system, continuous track rails, a bond of negligible impedance connecting the opposite rails of the track, a source of electric current arranged to create a difference of potential between the opposite rails of the track at a point distant from said bond, and an electro-responsive signal controlling device connected with the rails at a point intermediate the source and bond so as to receive a substantial working current determined by the drop of potential in a definite portion of the track between said bond and said source.

5. In a railway signaling system, electrically continuous track rails, a source of electric current arranged to create a difference of potential between the opposite rails of the track, a bond connecting the opposite rails and determining a point of substantially zero difference of potential between the rails, and an electro-responsive device receiving a substantial working current determined by the drop of potential in a portion of the circuit of said source, rails and bond.

6. In a railway signaling system, electrically continuous track rails, a source of electric current arranged to create a difference of potential between the opposite rails of the track, a bond connecting the opposite rails and determining a point of substantially zero difierence of potential between the rails, and an electro-responsive device connected to the track rails at points intermediate said source and bond to receive substantial working current determined by the drop of potential in a portion of the circuit composed of said source, rails and bond.

7. In a railway signaling system, track rails, a source of electric current arranged to create a difference of potential between the opposite rails of the track, a bond connecting the opposite rails and determining a point of substantially zero diderence of potential between the rails, and an electroresponsive device connected across the rails at points intermediate said source and bond so as to receive a substantial working current from the rails.

8. In a railway signaling system, a conductively continuous track, a pair of conducting bonds each connecting the opposite rails of the track, an electric source arranged to create a difference of potential between said rails at a point about midway between said bonds, two electro-responsive devices each connected with the rails at the opposite side of the source from the other at points between a bond and the source to receive substantial working currents determined by the drop of potential between said points and bonds, and a signal actuated upon the deenergization of either of said devices.

9. In a railway signaling system, conductively continuous track rails, a pair of conducting bonds each connecting the opposite rails of the track, a source of electric current connected between said opposite rails at a point about midway between said bonds, two electro-responsive devices each connected to the rails at the opposite side of the source from the other at points between a bond and the source to receive substantial working currents determined by the drop of potential between said points and bonds, and a signal actuated by the deenergization of either of said devices.

10. In a railway signaling system, a conductively continuous track, a pair of conducting bonds each connecting the opposite rails of the track, an electric source arranged to create a difference of potential between said rails at a point about midway between said bonds, two electro-responsive devices each connected across the rails at the opposite side of the source from the other at points between a bond and the source, and a signal actuated upon the deenergization of either of said devices.

11. In a railway signaling system, a conductively continuous track, a pair of conducting bonds each connecting the opposite rails of the track, an electric source connected between said opposite rails at a point about midway said bonds, two electro-responsive devices each connected across the rails at the opposite side of the source from the other at points between a bond and the source, and a signal actuated upon the deenergization of either of said devices.

12. In a railway signaling system, a conductively continuous track, a pair of conducting bonds each connecting the opposite rails of the track, an electric source arranged to create a difference of potential between said opposite rails at a point about midway between said bonds, two electro-responsive devices each connected across the rails at the opposite side of the source from the other at points between a bond and the source and relatively near to said bonds, and a signal actuated by the deenergization of either of said devices.

13. In a railway signaling system, conductively continuous track rails, a pair of conducting bonds each connecting the opposite rails of the track, an electric source arranged to create a difference of potential between said opposite rails at a point about midway between said bonds, two electro-responsive devices each connected with the rails at the opposite side of the source from the other at points between a bond and the source to receive substantial working currents determined by the drop oi potential between said points and bonds, a local circuit controlled by either of said electro-responsive devices, and signaling means controlled by the current in said local circuit.

14. In a railway signaling system, conductively continuous track rails, a pair of con ducting bonds each connecting the opposite rails of the track, a source of electric current connected between said opposite rails at a point about midway between said bonds, two electro-responsive devices each connected with the rails at the opposite side of the source from the other at points between a bond and the source to receive substantial working currents determined by the drop of potential'between said points and bonds, a local circuit controlled by either of said electro-responsive devices, and signaling means controlled by the current in said local circuit.

15. In arailway signaling system, a conductively continuous track, a pair of conducting bonds each connecting the opposite rails of the track, an electric source arranged to create difference of potential between said rails at a point about midway between said bonds, two electro-responsive devices each connected across the rails at the opposite side of the source from the other at points between a bond and the source, and signaling means actuated upon the deenergization of either of said devices.

16. In a railway signaling system, a conductively continuous track, a pair of conducting bonds each connecting the opposite rails of the track, a source of supply connected between said opposite rails at a point about midway of said bonds, two electroresponsive devices each connected across the rails at the opposite side of the source from the other at points between a bond and the source, a local circuit controlled by either of said electro-responsive devices, and signaling means controlled by the current in said local circuit.

17. In a railway signaling system, a conductively continuous track, a pair of conducting bonds each connecting the opposite rails of the track, an electric source arranged to create a dilference of potential between said opposite rails at a point about midway of said bonds, two electro-responsive devices each connected across the rails at the opposite side of the source from the other at points between a bond and the source and relatively near to said bonds, a local circuit controlled by either of said electro-responsive devices, and signaling means controlled by the current in said circuit and actuated by the deenergization of either of said devices.

18. In a railway signaling system, conductively continuous track rails, a series of conducting bonds connecting the opposite rails of the track, a series of current supply sources arranged to create a difference of potential between the opposite rails of the track at points between said bonds, a series of electro-responsive signal controlling devices each operatively related to the track rails to receive a substantial working current determined by the drop in potential in a definite portion of the track between a source and an adjacent bond, and signaling means controlled by the signal controlling devices.

19. In a railway signaling system, a source of electric current connected with the opposite track rails which are electrically continuous, a conductive cross-bond connecting the opposite track rails to complete a circuit including the source of current and track rails and bond, an electro-responsive signal-controlling device operatively related to the track rails to receive a substantial working current determined by potential difference established between separate points in the said circuit by flow of current from its said source, and automatic current-limiting means responsive to an excessive potential difference between the said separate points and arranged to limit the current transmitted to the electro-responsive device.

20. In a railway signaling system, a source of electric current connected .with the opposite track rails which are electrically continuous, a conductive cross-bond connecting the opposite track rails to complete a circuit including the source of current and track rails and bond, an electroresponsive signal-controlling device operatively related to the track rails to receive a substantial working current determined by potential difference established between separate points in the said circuit by flow of current from its said source, and an overload circuit-breaker arranged to transmit normal currents to the electro-responsive device but operated by an excessive transmission of current to arrest such excessive transmission.

21. In a railway signaling system, electrically continuous track rails, a' source of electric current supplying the opposite track rails at a point along the railway, a crossbond conductively connecting the opposite rails at another point to complete a circuit including the current source and rails and cross-bond, an electro-responsive signalcontrolling device operatively related to the track rails to receive a substantial working current determined by potential difference between the opposite rails at a point on the railway between the current source and bond, and automatic current limiting means in control of transmission of current to the electro-responsive device and in turn controllable by the said potential difference determining the current in the electro responsive device.

22. In a normal danger railway signaling system, a series of signaling blocks of the railway track, in each block a source of signaling current connected to the opposite rails between the ends of the block, in each block two electro-responsive signal-controlling devices deriving signaling current from the rails near the opposite ends of the block respectively, for each block an electrically controllable signal, and for a given block a signal actuating circuit in control of the signal of that block and in turn controllable by both electro-responsive devices of the given block and by one electro-responsive device of the block in rear.

23. In a normal danger railway signaling system, a conductively continuous railway track, cross-bonds conductively connecting the opposite track rails to define successive signaling blocks demarcated by the crossbonds, for each block a source of signaling current arranged to deliver current to the track rails between the ends of the block and thence in either direction through two oppositely extending rail circuits each including the rails and the bond at one end of the block, for each block two electro-responsive devices having connections respectively with the oppositely extending rail circuits and at points near the ends of the block, for each block an electrically controllable signal, and for each block a signal-actuating circuit in control of the signal for that block and controllable in turn by both electro-responsive devices of that block and also by an electro-responsive device of the block next in rear.

24:. In a home-and-distant normal-danger insane nal, and suitable intermediary circuits and means whereby the home signal of the given block is governed by both electro-responsive devices of that block and by an electro-responsive device of a block in rear and whereby the distant signal of the given block is governed by. both electro-responsive devices given block a home signal and a distant signal, for the given block a signal actuating circuit in control of the home signal of that block and in turn controllable by both electro-responsive devices of that block and also by an electro-responsive device of a block in rear, a relay or circuit-controlling device controlled by the said signal actuating circuit, and another signal actuating circuit in control of the distant signal of the given block and in turn controllable by the relay or circuit-controlling device last mentioned and also by both electro-responsive devices of the block in advance of the given block.

26. In a home-and-distant normal danger railway block-signaling system, a conductively continuous railway track, conductive cross-bonds connecting the opposite track rails at intervals to demarcate successive signaling blocks terminating at the crossbonds, for each block a source of signaling current connected with the opposite track rails between the ends of the block, for each block two electro-responsive devices having connections with the block rails near the opposite ends of the block respectively, for v a given block a home signal and a distant signal, and suitable intermediary circuits and means whereby the home signal of the given block is governed by both electro-responsive devices of that block and by an electro-responsive device of a block in rear and whereby the distant signal of the. given block is governed by both electro-responsive devices of the blocknext inadvance and also by the said three eleotro-responsive devices which govern the home signal of the given block.

27. In a home-and-distant normal danger railway block-signaling system, a conductively continuous railway track, conductive cross-bonds connecting the opposite track rails at intervals to demarcate successive signaling blocks terminating at the cross bonds, for each block a source of signaling current connected with the opposite track rails between the ends of the block, for each block two electro-responsive devices having connections with the block rails near the opposite ends of the block respectively, for

a given block a home signal and a distant signal, for the given block a signal actuating circuit in control of the home signal of that block and in turn controllable by both eleotro-responsive devices of that block and also by an electro-responsive device of a block in rear, a relay or circuit-controlling device controlled by the said signal actuating circuit, and another signal actuating circuit in control of the distant signal of the given block and in turn controllable by the relay or circuit-controlling device last mentioned and also by both electroresponsive devices of the block in advance of the given block.

28. In a railway signaling system, the track having conductively continuous rails, sources of electric supply feeding the same at intervals, means for fixing points of substantially zero difierence of potential between the rails intermediate successive sources, an electro-responsive device con nected across the rails at each side of each of said zero points, so as to receive substantial working current determined by the drop of potential in a definite portion of the track between the adjacent bond and source, and signals in operative relation with said devices.

29. In a railway signaling system, the track having conductively continuous rails, sources of electric supply feeding the same at intervals, means for fixing points of substantially zero diiierence of potential between the rails intermediate successive sources, an electro-responsive device connected across the rails at each side of and relatively near each of said zero points, and signals in operative relation with said devices.

30. In a railway signaling system, a source of signal controlling current, electrically continuous rails having a closed track circuitsupplied by said source an electro re- 31. In a railway signaling system, a series of sources of signal controlling current, a track having conductively continuous rails energized by said sources and means for forming a series of normally closed track circuits fed by such sources said means forming points of substantially zero difference of potential between the rails, and electroresponsive devices connected across the rails at points at each side of and relatively near said zero points.

32. In a railway signaling system, a series of sources of signal controlling current, a

of sources of signal controlling current, a

track having conductively continuous rails connected at intervals by negligible impedance bonds to form a series of normally 'closecltrack circuits fed by such sources, and

electro-responsive devices connected across the rails at points. at each side tively near said bonds.

34. In a railway signaling system, a series of sources of signal controlling current, a track having conductively continuous rails connected at intervals by negligible impedance bonds to form a series of normally closed track circuits fed by such sources, transformers each having its primary connected across the rails at one side of and relatively near one of said bonds, and electro-responsive devices each in operative relation with the secondary of one of said transformers.

35. In an electric railway system, a series of sources of signal controlling current, a track having conductively continuous rails energized by-said sources and means forming a series of normally closed track circuits fed by such sources said means forming points of substantially zero difference of potential between the rails, electro-responsive devices connected across the rails at points at each side of and relatively near said zero points, and a source of traction current having one side connected to said track.

of and relatrack having conductively continuous rails energ zed by said sources and means forming a series of normally closed track circuitsfed by such sources said means forming points of substantially zero difference of potential between the rails, transformers each having its primary connected across the rails at one side of and relatively near one of said zero points, electro-responsive devices 'each'in operative relation with the secondary of one of said transformers, and a source of traction current having one side connected to said track.

37. In an electric railway system, a series of sources of signal controlling current, a track having conductively continuous rails connected at intervals by negligible impedance bonds to form a-series of normally closed track circuits fed by such sources, electro-responsive devices connected across the rails at points at each side of and relatively near said bonds, and a source of traction current having one side connected to said track.

38. In an electric railway system, a series of sources of signal controlling current, a track having conductively continuous rails connected at intervals by negligible impedance bonds to form a series of normally closed track circuits fed by such sources, transformers each having its primary connected across the rails at one side of and relatively near one of said bonds, electroresponsive devices each in operative relation with the secondary of one of said transformers, and asource of traction current having one side connected to said track.

39. In a block signal system, in combination with an electric railway having both rails conductively continuous for all currents, sources of alternating current connected across the rails at intervals, track relays connected in shunt to short lengths of rail, the relays and short rail lengths having such relative impedance as to produce a substantial working current in the relay, and signals controlled by said relays.

40. In a block signal system, in combination with an electric railway having both rails conductively continuous for all currents, sources of alternating current connected across the rails at intervals, signaling devices for controlling the signals connected in shunt to short lengths of rail, the relative impedance of the paths in shunt to each other being such as to enable an effective voltage to be applied to the signaling device, and signals controlled by said signaling devices.

41. In a block signal system, in combination with an electric railway a track com- .posed of two continuous rails, a source of v alternating current connected across the 36. In an electr1c railway system, a series of sources of slgnal controlling current, a

rails, a bond of low impedance connected across the rails at a distance from said source, a signaling device for controlling the signal connected in shunt to a short length of rail between the source and the bond, the relative impedance of the paths in shunt to each other being such as to enable an eifective voltage to be applied to the signaling device, and a signal controlled by the signaling device.

42. Ina block system, in combination with an electric railway a track composed of two continuous rails, sources of alternating current connected across the rails at intervals,

bonds of low impedance connected across other being such as to enable an efl'ective voltage to be applied to the signaling device, and signals controlled by said signaling devices.

43. In a block signal system, in combination with an electric railway having both rails conductively continuous for all currents, sources of alternating current connected across the rails at intervals, signal controlling devices, each having a winding supplied with energy by current shunted around impedance in the track circuit, a substantial portion of said impedance consisting of track rail impedance, the relative impedance of the paths in shunt to each other being such as to direct through said winding a substantial portion of the energy supplied to the winding.

44. In a block signaling system for electric railways, means providing for block signaling while maintaining the opposite traflic rails continuous throughout the blocks and from block to block comprising spaced cross-bonds cross connecting the opposite rails for all currents and demarking the blocks; a translating device; means for impressing a high frequency alternating potential between points on the opposite traffic rails, said points being located intermediate two adjacent cross-bonds; means for utilizing inductive reactance inherent in the steel of the'rails of a block for operatively energizing said translating device when the block is clear and being inoperative to cause the operative energization of said translating device when sufiicient length of traflic rail in a block is shunted by a train in the block.

45. In a block signaling system for electric railways, opposite traffic rails continuous from block to block and throughout each block; spaced cross-bonds demarking a block; a translating device; means for impressing a high frequency alternating potential between points on the opposite traflic rails, said points being located intermediate two adjacent cross-bonds; means for utilizing inductive reactance inherent in the steel of the rails of a block for operatively energizing said translating device when the block is clear and being inoperative to cause the operative energization of said translating device when sufficient length of traflic rail in a block is shunted by a train in the block.

In testimony whereof, I have signed my name to this specification, in the presence of two subscribing witnesses.

HERBERT A. WAGNER.

Witnesses:

BERNARD CownN, WM. Asnnnv KELLY.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. G. 

